Evidence suggests that regression and progression of localized breast cancer, after the disease has been diagnosed and treated by conventional means, might be reduced by 30-50% if current dietary guidelines for Americans were enriched markedly for edible plants and fiber and had a reduced fat content. The Women's Healthy Eating and Living (WHEL) study, a multi-center randomized trial, will test the effect of a diet composed of 15-20% of calories from total fat, = 30 gm of fiber/day, and twice the vegetable and fruit goals of the National Cancer Institute (NCI) dietary recommendations of 5 servings/day, with an emphasis on consuming "nutrient-dense" vegetables, i.e. those with a high content of antioxidants and specific phytochemicals. Medical follow-up is by usual oncology practice to determine clinical study endpoints of disease-free and total survival. The goal is to enroll 3000 breast cancer survivors over a 4-year period, who are within 4 years of their diagnosis of stage I (>1 cm), II and IIIA disease and who have completed conventional therapy. The Northern California Cancer Center, as one of six clinical centers, will enroll 500 women who will be tested and followed at the Stanford and University of California, San Francisco, General Clinical Research Centers. In addition, to telephone counseling by staff at the USCD Coordinating Center, women will attend regular cooking classes directed by registered dietitians who may also provide interim counseling. WHEL will determine if the risk of recurrence can be reduced by 20% at 6 years. To gain insight into mechanisms of how diet might influence the disease, WHEL will compare plasma carotenoids and endogenous estrogen levels in women who have a secondary cancer event with levels in women who have not yet recurred, but who are matched for other characteristics from both the study and control groups.